This invention relates in general to an airstream heater and more particularly to a heater having a gas burner for heating an airstream from within the airstream.
The direct heating of an airstream by means of an airstream burner yields particularly desirous results, especially for certain applications. Dry, fresh air can be introduced into an area when cold outside air is introduced into the heater. When the area of introduction is a greenhouse, better plant growth can be achieved. This is in part due to the fact that fresh air and good ventilation is provided. Also, the amount of insects and bacteria are reduced by the presence of warm, dry fresh air. In fact, during cold weather, many greenhouses heated by other means experience a condition known as "damp off". This occurs when an inordinate amount of condensation forms in the greenhouse which contributes to root rot of the plants therein. The dry air from a heater as described above can eliminate this problem.
When the area of introduction is a chicken house, better bird growth can be achieved. As with the greenhouse application, good ventilation is afforded and the dry fresh air reduces the presence of harmful bacteria. Also, the amount of ammonia produced from the bird droppings within the building can be reduced and building sweating can be eliminated. All this provides an environment for the birds which stimulates their appetites and gives better feed conversion. One way this is achieved is by the dry heat promoting more water consumption and greater growth rates. Additionally, the heater itself is safer than conventionally used chicken house heaters. No open flame is utilized as with the conventional heaters in what is normally a high risk fire area with materials such as loose straw and methane generally present.
Other areas can be heated by means of direct contact type heaters with similarly beneficial results. However, to efficiently and effectively heat any area with such type heater, the heating of the airstream must be rapid and thorough. This is a particularly difficult endeavor when the flow rate of the airstream is high which is generally desirable so that the heating unit will not have to operate as long to heat a given area. Problems often encountered are maintenance of the burner flame in the airstream and inadequate temperature rise of the airstream within the heater. To overcome such type problems, rather complex structures have been proposed. One such structure is disclosed in U.S. Pat. No. 4,023,923 to Kramer.